1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
|
/*
* decompress.c
*
* Detect the decompression method based on magic number
*/
#include <linux/decompress/generic.h>
#include <linux/decompress/bunzip2.h>
#include <linux/decompress/unlzma.h>
#include <linux/decompress/unxz.h>
#include <linux/decompress/inflate.h>
#include <linux/decompress/unlzo.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/init.h>
#ifndef CONFIG_DECOMPRESS_GZIP
# define gunzip NULL
#endif
#ifndef CONFIG_DECOMPRESS_BZIP2
# define bunzip2 NULL
#endif
#ifndef CONFIG_DECOMPRESS_LZMA
# define unlzma NULL
#endif
#ifndef CONFIG_DECOMPRESS_XZ
# define unxz NULL
#endif
#ifndef CONFIG_DECOMPRESS_LZO
# define unlzo NULL
#endif
struct compress_format {
unsigned char magic[2];
const char *name;
decompress_fn decompressor;
};
static const struct compress_format compressed_formats[] __initconst = {
{ {037, 0213}, "gzip", gunzip },
{ {037, 0236}, "gzip", gunzip },
{ {0x42, 0x5a}, "bzip2", bunzip2 },
{ {0x5d, 0x00}, "lzma", unlzma },
{ {0xfd, 0x37}, "xz", unxz },
{ {0x89, 0x4c}, "lzo", unlzo },
{ {0, 0}, NULL, NULL }
};
decompress_fn __init decompress_method(const unsigned char *inbuf, int len,
const char **name)
{
const struct compress_format *cf;
if (len < 2)
return NULL; /* Need at least this much... */
for (cf = compressed_formats; cf->name; cf++) {
if (!memcmp(inbuf, cf->magic, 2))
break;
}
if (name)
*name = cf->name;
return cf->decompressor;
}
|
